Synthesis, characterization and extraction studies of a new vic-dioxime and its complexes containing bis(diazacrown ether) moieties

A new vicinal dioxime ligand containing bis(diazadioxa-12-crown-4 ethoxy) units (H2L) has been synthesized by the reaction of cyanogendi-N-oxide with 3,4-bis(2-{10-[(4-methylphenyl)sulfonyl]-1,7-dioxa-4,10-diazacyclododecan-4-yl}ethoxy)aniline, which was prepared by the reduction of 4-[(4-methlyphenyl)sulfonyl]-10-[2-((4-nitro-2-{2-[10-phenylsulfonyl)-1,7-dioxa-4,10-diazacyclododecan-4-yl]ethoxy}phenoxy)ethyl]-1,7dioxa-4,10-diazacyclododecan. A mononuclear nickel(II) and copper(II) complexes with a metal:ligand ratio of 1:2 for H2L were also synthesized. The mononuclear cobalt(III) complex of H2L has been isolated with L′ = pyridine, together with chlorine as an axial ligand. In addition, a cobalt(III) complex containing the BF2+ bridge macrocycle was synthesized using a precursor hydrogen-bridged cobalt(III) complex via the template effect. The extraction abilities of 1, 3, 6 and 10 were also evaluated in 1,2-dichloroethane by using several alkali (Li+, Na+, K+, Cs+) and transition metal picrates such as Ag+, Pb2+, Cd2+, Cu2+, Zn2+. The structure of the dioximes and their complexes are proposed according to elemental analyses, 1H and 13C NMR, FT-IR UV-Vis and mass spectra. © 2006 Elsevier Ltd. All rights reserved